How can I access Docker containers Folder and files from Windows file explorer?
If you are running Docker Desktop on Windows, Docker containers don't run natively on the local filesystem, but instead on a hyper-v virtual machine or via WSL2.
Hyper-v (legacy)
In theory, if you were to stop the hyper-v vm, you could open up the vhdx, and if you had the right filesystem drivers, mount it and see the files inside. This is not possible to do while the virtual machine is running. By default the OS that runs for Linux container mode is named "Docker Desktop", but runs busybox.
The file could be found here:
C:\ProgramData\DockerDesktop\vm-data\DockerDesktop.vhdx
WSL2 (modern)
WSL things are slightly different, but not much. You are still effectively working with a virtual environment.
One of the nice advantages of WSL however, is that you can actually browse this file system naively with Windows Explorer.
By browsing to \\wsl$ you will be able to see the file systems of any distributions you have, including docker-desktop.
The docker filesystems on my machine seem to live in:
\\wsl$\docker-desktop-data\version-pack-data\community\docker\overlay2
However, the overlay 'merged' view, which shows the original file system with your changes, doesn't seem to work via windows explorer and gives you a blank window. You can however still see the 'diff' folder, which contains your changes.
You can open a terminal to either of these instances by using the wsl command, from powershell.
Access via Docker
If you wanted to have a look at this Docker OS and filesystem, one way would be to spin up a container, that has access to the OS at the root, something like:
docker run -it --mount type=bind,source=/,target=/host ubuntu /bin/bash
This should drop you into a Ubuntu docker container, with a Bash terminal, which has the root of the hyper-v container (/), mounted on the path '/host'. Looking inside, you will find the Busybox filesystem of the virtual machine that is running docker, and all the containers.
Due to how docker runs, you will be able to access the filesystems of each container. If you are using the overlay2 filesystem for you containers, you would likely find the filesystem layers here for each container:
/host/var/lib/docker/overlay2
If the files you want to browse through in windows explorer, you should be able to configure a samba export of this folder, that is accessible from the host machine, that is accessible while this container is running.
If the goal however is to be able to browse/edit files on the local OS, and have them update inside the container, normally the easiest way to do this, is to mount local directory into the container. This can be done similar to the example above, but you first need to go into the Docker Desktop settings, and enable the mounting of the shared drive into the host virtual machine, and then provide the volume argument when you spin up a container.
If you are using WSL2, there are a few more options available to you, as you can keep your projects inside the WSL layer, while interacting with them from the host OS or via docker. Best practice for this is still in flux, so I'm going to avoid giving direct advice here.
Another related question's reply answers this: https://stackoverflow.com/a/64418064/1115220
\\wsl$\docker-desktop-data\version-pack-data\community\docker\volumes\
I'll give WordPress app as an example by showing a sample of the docker-compose.yaml file. In order to have project files shown in windows from docker container, you'll need to use ports and volumes
Notice volume and ports.
port 8000 from the local machine maps to 80 within the container.
as for volume, ./ current directory on windows maps to the container image files.
wordpress:
depends_on:
- db
image: wordpress:latest
volumes: ['./:/var/www/html']
ports:
- "8000:80"
restart: always
environment:
WORDPRESS_DB_HOST: db
WORDPRESS_DB_USER: wordpress
WORDPRESS_DB_PASSWORD: wordpress
WORDPRESS_DB_NAME: wordpress
When running Windows container on Windows Docker Desktop, I was able to see all image files here:
C:\ProgramData\Docker\windowsfilter
(requires admin rights to access, and it would be unwize to delete/modify anything there)
Further, with WizTree tool, it's easy to see real sizes of each image layer and even find which specific files contribute to layer's size.
You should use a mount volume. In your docker run .... command, you may specify a mount volume. The syntax is as follows:
-v /host/directory:/container/directory
An example:
docker run -it -v C:\Users\thomas\Desktop:/root/home --name my_container image1
This would allow the container to write files to /root/home and have them appear on the user thomas' desktop
Related
I've reviewed the documentation here:
https://docs.docker.com/docker-for-mac/install/#install-and-run-docker-for-mac
It doesn't say anything about boot2docker, although some other questions along these lines talk about this:
Mount volume to Docker image on OSX
So the question is – the Docker for Mac application provides File Sharing via Preferences -> File Sharing; how does one make use of these shared folders from the docker image (for example if one ssh's into the docker image)? When I say how, I don't mean "what are the use-cases", I mean "please show me an example of how to access a shared folder from the command line of the running container".
Ideally I'm trying to create a similar scenario to Vagrant's synched folders whereby I can edit files on my Host env, independently of the Docker Image but these are updated automatically to the Docker image on save.
UPDATE:
To be clear, the reason for asking this question is because I couldn't get the -v docker command to work. E.g.
docker run -v /Users/geoidesic/Documents/projects/arc/mysite/djangocms_demo:/home/djangocms/djangocms/djangocms_demo -d -p 8001:8000 --name test_shared_volumes bluszcz/djangocms
With the above command the container immediately stops, so if I run docker ps the list of running containers is empty.
However, if I run the container without the -v command, then it stays running as expected:
docker run -d -p 8001:8000 --name test_shared_volumes bluszcz/djangocms
Updated:
Well, if you want to share file/directory between host and container, you're gonna use Docker's bind-mount.
For example, if I want to share my host's /etc/resolv.conf to my container, I do the following:
docker run -v /etc/resolv.conf:/etc/resolv.conf <IMAGE>
In which the -v ... part tells the container to reuse host's /etc/resolve.conf. And whenever I edit this file, the changes will be immediately visible to the container.
In Linux, you can use this way to share almost any of your host files to containers. Unfortunately, this is not the case for Mac. As I mentioned in my old answer, by default you can only share /Users/, /Volumes/, /private/, and /tmp directly.
On my Mac, saying, I want to share the /data directory to a container. I run below command:
docker run -it --rm -v /data:/data busybox sh
Then it pops up an unhappy error:
docker: Error response from daemon: Mounts denied:
The path /data
is not shared from OS X and is not known to Docker.
You can configure shared paths from Docker -> Preferences... -> File Sharing.
See https://docs.docker.com/docker-for-mac/osxfs/#namespaces for more info.
So you see, this is where File Sharing comes up.
Then comes my answers to your questions:
File Sharing does not provide you a ready-to-use way to do the sharing as you have experienced in Vagrant;
To share file/folder between host and container, use Dockers bind-mount.
Hope that helps.
Old answer:
File Sharing is used by Docker's bind-mount feature. By default, you can bind-mount files in /Users/, /Volumes/, /private/, and /tmp directly. For other paths, you need to add them to Preferences -> File Sharing first.
Use cases for bind-mount:
Persisting data generated by the running container, so that you can backup or migrate data.
Sharing data amount multiple running containers.
Share host configuration files to containers.
Share source code between host and containers, to make debugging easier.
Note: For cases #1 and #2, consider using volumes instead of bind-mount.
I have a container that I start like
docker run -it --mount type=bind,source=/path/to/my/data,target=/staging -v myvol:/myvol buildandoid bash -l
It has two mounts, one bind mount that I use to get data into the container, and one named volume that I use to persist data. The container is used as a reproducable android (AOSP) build environment, so not your typical web service.
I would like to access the files on myvol from the Windows host. If I use an absolute path for the mount, e.g. -v /c/some/path:/myvol, I can do that, but I believe docker creates copies of all the files and keeps them in sync. I really want to avoid creating these files on the windows side (for space reasons, as it is several GB, and performance reasons, since NTFS doesn't seem to handle many little files well).
Can I somehow "mount" a container directory or a named volume on the host? So the exact reverse of a bind mount. I think alternatively I could install samba or sshd in the container, and use that, but maybe there is something built into docker / VirtualBox to achive this.
Use bind mounts.
https://docs.docker.com/engine/admin/volumes/bind-mounts/
By contrast, when you use a volume, a new directory is created within Docker’s storage directory on the host machine, and Docker manages that directory’s contents.
I am unable to find the location where images and containers are stored in my machine, i checked this and with 'docker info' in Docker Root Dir i have /var/lib/docker , but i'm unable to find this anywhere,
They live under C:\ProgramData\docker
(This is for case of WSL2.)
Docker images are managed by docker's own VM. The path /var/lib/docker given by "docker info" is relative to docker's host file system, not your container's file system. The mount points are different for them. You can view docker's host file system in either of the following ways:
You can mount the host file system to a container directory. Such as,
docker run -v /:/data -it ubuntu /bin/bash
This command runs a shell in Ubuntu docker image, mounting docker's file system to /data directory. There you can find a complete file system under /data, including the ./var/lib/docker. If you want, you can "chroot /data" in the shell prompt to have a better view.
When docker is enabled with your distribution in WSL2, you can always check your containers in your distribution /mnt directory. Docker has mounted everything for you.
/mnt/wsl/docker-desktop-data/data/docker
If you are seasoned enough, you may find the actual location of the virtual disk of all the data in your Windows directory.
C:\Users\your_name\AppData\Local\Docker\wsl\data\
Or probably just for fun:
\\wsl$\Ubuntu\mnt\wsl\docker-desktop-data\data\docker
Unfortunately I haven't tried to dive into them.
I initially configured my docker setup for Docker for Windows. Everything worked great. I'm using docker-compose to define 3 containers, each of which have a volume being mapped from my ./src (path on host) to /src/ (path on container).
I recently found out that the production server might have Windows 10 Home, which doesn't support Docker for Windows. So, my thinking is that I should revert to docker toolbox to be prepared for that scenario.
So I uninstalled Docker for Windows and installed Docker toolbox. I can build my images with docker-compose build just fine, but now when I run docker compose up -d, 2 of my containers immediately crash because the /src/ directory never gets mounted.
I can verify that the volumes are not getting mounted by running docker exec -it ng01 bash and seeing that the volume directory exists but is empty. 2 of my co-workers can reproduce this issue on their windows machines with docker toolbox.
Does anyone know why this is happening, or how to get around it? I've been looking at a bunch of similar SO posts, but the various solutions have gotten me nowhere. I would appreciate some guidance.
Here is my docker-compose file.
I have my source code in src/.
I have my Dockerfiles in docker/
Here is hotloader.Dockerfile.
Here is web.Dockerfile. I don't think they are the issue, but I might as well share them anyways.
Thank you in advance!
Docker Toolbox for Windows works by setting up a VirtualBox VM named default. Running any docker command forwards that command to the VM (Windows Machine → Virtual Machine → Docker).
To mount local Windows folders as Docker volumes, those folders first need to be shared and mounted on the VM that is running Docker.
By default, C:\Users is shared, so mounting volumes from that location will work without any configuration.
So you can either move your project on this already shared location(C:\Users) or you can follow the steps in this document https://headsigned.com/posts/mounting-docker-volumes-with-docker-toolbox-for-windows/
Hope this helps! :)
I'm trying to mount a network folder with a Docker container on Windows 10 with the following syntax. Using UNC paths does not work. I'm running it under Hyper-V and the stable version of Docker.
docker run -v \\some\windows\network\path:/some/local/container
Before I was using Docker Toolbox, and I could map a network share to an internal folder with VirtualBox. I've tried adding the network share as a drive, but it doesn't show up as an available drive under the settings panel.
Currently I'm using mklink to mirror a local folder to the network folder, but I'd like to not depend on this as a solution.
Do this with Windows based containers
Go to Microsoft documentation https://learn.microsoft.com/en-us/virtualization/windowscontainers/manage-containers/persistent-storage#smb-mounts.
There you'll find information about how to mount a network drive as a volume in a windows container.
Do this with Linux based containers
Is currently (as of 2019-11-13) not possible. BUT you can use a plugin: https://github.com/ContainX/docker-volume-netshare
I didn't use it, so I have no experience with it. Just found it during my research and wanted to add this as a potential solution.
Recommended solution
While researching on this topic I felt that you should probably mount the drive from within the container. You can pass required credentials either via file or parameters.
Example for credentials as file
You would require to install the package cifs-utils in the container, add
COPY ./.smbcredentials /.smbcredentials
to the Dockerfile and then run the following command after the container is started:
sudo mount -t cifs -o file_mode=0600,dir_mode=0755,credentials=/.smbcredentials //192.168.1.XXX/share /mnt
Potential duplicate
There was another stackoverflow thread on this topic here:
Docker add network drive as volume on windows
The answer provided there (https://stackoverflow.com/a/57510166/12338776) didn't work for me though.